I have a slightly obscure problem :) For testing purposes we're running opencl inside a linux VM, so the actual gfx hardware is not accessable. We're using the CPU fallback from intel's opencl impl instead. Apparently, this impl is using TBB to get better performance but our environment does not allow for third parties to create any threads. We don't need any performance, just that it works at all. Is there a way (maybe by setting an environment variable) to disable the multi-threading inside intel's CPU based opencl driver?